This proposal is for Phase 1 of the proposed Trial of Hypertension Prevention, a feasibility study to determine a non-pharmacologic regimen for the prevention of sustained hypertension. A total of 200 men and women with qualifying diastolic blood pressure, 80--94 mmHG at second screening, and ages 25-49 at entry with body weight at least 10% above ideal weight, will be recruited over a nine month period. Eligible participants will be randomly assigned one of four treatment groups; 1) control, 2) weight control, 3) exercise training, or 4) weight control and exercise training. The weight control groups will have the goals of reducing caloric intake and increasing caloric expenditure in order to reduce mean body weight at least 5%. The training groups' goal will be to achieve at least a mean 10% increase in maximal exercise capacity. This Phase 1 feasibility study involves nine months of planning and nine months of recruitment with long-term follow-up of approximately 27 months allowing 3 months for final data analysis and transition to Phase 2 of the study should it be warranted. The primary objectives for this phase of the trial is to test the feasibility of providing and obtaining compliance with the nutritional/exercise interventions, and to measure the short-term effectiveness of the interventions in reducing or preventing an increase in diastolic blood pressure. Final decisions regarding the intervention modality and a common protocol with standard measurements and outcome events would await a common protocol designed by the collaborating clinics as a whole in cooperation with the coordinating center and the National Heart, Lung and Blood Institute.